Device comprising one or more push buttons



Dec. 9, 1958 F. LAMPE ET AL 5 DEVICE COMPRISING ONE' OR MORE PUSHBUTTONS Filed July 20, 1955 INVENTORS FREDRKH LAHPE FRIEDRlCH LAA UnitedStates Patent M DEVICE COMPRISING ONE OR MORE PUSH BUTTONS FriedrichLampe and Friedrich Laa, Vienna, Austria, as-

signors, by mesne assignments, to North American Philips Company, Inc.,New York, N. Y., a corporation of Delaware Application July 20, 1955,Serial No. 523,247

Claims priority, application Austria September 10, 1954 5 Claims. (Cl.200-18) This invention relates to a push-button arrangement of the typeused in radio apparatus. In a known structure comprising one or morepush buttons and a locking member preferably for each individual pushbutton has been suggested, each push button being supported by aswitching element comprising the locking member, which switching elementis slidable in the pushing direction for controlling a switchingmechanism and is tiltable about an axis, preferably imaginary, at rightangles to the direction of sliding for locking or releasing the lockingmember.

Consequently, it is possible by means of each button to choose betweentwo positions of the switching mechanism.

The invention underlies the recognition that during the tilting movementat least part of the switching element may exhibit a component ofmovement oppositely directed to the corresponding direction of sliding,that is to say after a button has been pushed, an opposite movement ofpart of the switching element may follow during tilting, and when abutton is released, a movement opposite to the subsequent slidingmovement may occur during tilting. Consequently, during pushing andlocking and also during the release and the subsequent sliding movementthe movement of part of the switching element may each time be reversed.

For demagnetising recording heads and reproducing heads in magneticrecorders numerous circuits are known for preventing or obviatingresidual magnetism. In a known simple method the head is connected to acharged capacitor of corresponding capacity to form an oscillatorycircuit. The decreasing oscillations with which the capacitor thendischarges cause the head to be demagnetised completely. The circuitthus consists in that the connection between the head and the amplifieris interrupted, a connection between the head and the capacitor isestablished and then interrupted again, and at last the head is againconnected to the amplifier. This sequence of switching operations may,of course, be brought about in a very simple manner .by arbitraryoperation of the switch. However, it is common practice that thissequence of switching is effected automatically by operation of themembers for recording and reproduction.

According to the invention, at least part of the switching elementduring tilting exhibits a component of movement oppositely directed tothe corresponding direction of sliding, said component of movement beingused to control the switching mechanism, so that the change in positionthereof is limited to part of the operating time of the device.

Consequently, the device according to the invention permits not only ofbringing about a permanent change in position of a switching mechanismbut also of obtaining a change in position for a determined period. Thespeed of the movement of the button only acts upon the duration of thechange in position. Irrespective of this speed, however, it is alwaysensured that the change in position actually takes place and is obviatedat the end of the operating period.

2,863,959 Patented Dec. 9,1958

In one advantageous embodiment of the device according to the invention,each part of the switching element on account of the particular shape ofthe locking surface of the locking member exhibits a component ofmovement oppositely directed to the corresponding direction of sliding,so that each arbitrary part of the switching element may be utilised tocontrol the switching mechanism.

In order that the invention may be readily carried into effect, it willnow be described, by way of example, with reference to the accompanyingdrawing showing an example of switching in a magnetic recorder forrecording and reproduction.

Figs. 1 and 2 show one embodiment comprising two buttons intended forrecording and reproduction, respectively.

Fig. 1 is a sectional view taken along the line I'I of Fig. 2, but inwhich, contrary to Fig. 2, the two buttons are assumed to-occupypositions.

Fig. 3 shows the button of Fig. 1 at the moment of being locked and iFig. 4 shows this button in the completely locked position.

A carrier plate 1 has secured to it a U-shaped clasp 23 by means ofrivets 24 and 25. The two tree limbs of the U are bent inwardly, thusforming extensions 26 and 27. An aperture 28 of the carrier plate 1 issuch that the switching elements 29 and 30 are not guided by it. This iseffected in apertures 31, provided in the extensions 26 and 27, and inapertures 32 of the clasp 23. Springs 33, 34 are secured, on the onehand, to extensions 35 and 36 of the switching elements 29 and 30 and,on the other, to extensions 37, 38 of the clasp 23. By means of a pin39, it is possible to operate a lever 40 connected by way of a rod 41 toa switching mechanism for recording or reproduction. The upward movementof the elements 29 and 30 is limited by the parts moved by them. Thedownward movement of the elements 29 and 30, if the elements have notbeen locked beforehand, is at any rate limited due to the extensions 35,36 abutting against the parts 26, 27. The elements 29, 30 are operatedby but tons 42, 43. The upper surfaces 44 thereof are of a particularshape to facilitate the operation.

A locking member 45 is of a shape such that at least an edge obtained byintersection of surfaces 46 and 47 and engaging in the locked positionwith the lower side of the U-clasp 23 remains in contact with the lowerside of the clasp 23 during tilting of the element 29. This takes place,for example, as shown in Fig. 5, in which the surface 46 is a flatsurface making an angle a with the surface 47 which is the complement ofan angle 19, that is the angle through which the surface 47 has beentilted. The locking member of lever 30 is of a similar shape. Owing tothis particular shape of the surface 46 1t 15 ensured that each part ofthe switching elements exhibits a component of movement which isopposite to the corresponding direction of sliding as long as the edgeof the surface 46 slides along the lower side of clasp 23. The terminusof the element, is indicated by 48 in the case of the element 29, thusin Fig. 3 is farther away from the lower side of clasp 23 than in Fig.4. The displacement in the direction of sliding of the element is duringtilting oppositely directed to the preceding or subsequent slidingmovement.

The reversal in the direction of movement of the elements 29 and 39during tilting is utilised to control the demagnetising device indicateddiagrammatically by springs 49, 50, 51.

The U-clasp 23 comprises, at each end, a prolongation 52 projecting fromthe extensions 26, 27, respectively. Between the prolongations 52, alever 54 is pivotally ar ranged on a shaft 53. The lever 54 ismaintained in a rest position by a spring 55 and an abutment 56 provided*ing movement. posed on the shaft, the magnitude and the direction ofthe "displacement resulting from the tilting movement 3 on "ala'teral'p'art 52, which rest position is chosen to be such that thepoints 48 just engage the lever 54 in the locked positions of theelements 29 and 31 The lever 54 occupies the same position when thebuttons are released. The lever "54ha's a suitably positioned thickenedpart 57 which causes the spring 50, which is in contact with the spring'49 at the -rest position of the lever 54,10 'be switched ove'r'to'thespring "51 "as soon as the lever 54 is pushed and brought out of itsrest position. This is effected automatically each time either of thetwo push buttons islocked and released.

When the-spring 50is connected to the magnetic head, the spring 49 isconnected to the amplifier and'the spring 51 is connected to thedem'agnetisation capacitor, it is found 'thateach switching operation ofthe butto'ns42, 43

involve demagnetisation of the head.

Since the distance-between the point 43 and the shaft '53 is very small,but the distance between the thickened part 57 and the shaft 53 iscomparatively large, a small shift 'of point 48 amounting to some tenthsof millimetres is su fficient to provide a suiii'cient stroke of thethickened part 57.

It will readily be evident that, during the tilting of the elements 29,30, the parts located under the apertures 31 and 32, respectively,perform movements, components of which are oppositely directed to thecorresponding slid- However, this tilting movement issuperbeing-determined by the shape of the surface 46. If the part of theelement projecting above the apertures 31, 32

is very long, the shift resulting from tilting is immaterial.

Consequently, it is advantageous for the surface 46 to have a shape suchthat the shifts of all parts of the element resulting from tilting issufficient to control the switching mechanism.

The present invention'is not limited to the use in connection with ademagnetising device. It is also independent of the manner in which thesliding movement of the switching element is transmitted, neither is itessential for the edge which during tilting slides along the lower edgeof clasp 23 to be located in the surface 47 and hence at the end of thesurface 46, though the maximum stroke is thus obtained. It is notnecessary for the movement of "apoint to be derived from the lowerextremity of the frame member secured to said carrier plate, at leastone switching element having a locking portion and slidable in saidframe member, a switch mechanism associated with said push-button deviceand controlled by the movement of said switching element, the latterbeing slidable in a direction substantially transverse to said switchmechanism to actuate the same and tiltable about an axis substantiallyperpendicular to the direction of sliding to further actuate said switchmechanism while said switching element is locked against further slidingmovement by said locking portion.

2. A push button device as set forth inclaim 1 further comprising anelongated lever engaging at one end :said switch mechanism, meanspivotally mounting said lever on said frame for transmitting themovement of said switching element. A

3. A push-button device as set forth in claim 2 wherein said lever is soconstructed that the same switch mechanism is controlled by differentswitching elements.

4. A push-button device comprising 'a carrier plate, a frame membersecured 'tos'aid carrier plate, at least one switching element having -alocking portion and 'slidable in said frame member, said locking portionbeing areentr'ant part having opposite sides angular-1y positionedrelative to each -other,'-the distance between said opposite sides.at'the opening of said re-entrant part being "smaller -=than thedistance between said opposite sides in the rear "of said "re-entrantpart, a switch mechanism associated withs'ai'd push-button device "andcontrolled by the movement of said switching element, the latter beingslidabl'e in a direction substantially transverse to said switchmechanism to actuate the same and tiltable about an axis substantiallyperpendicular to the direction ofsliding to further actuate said'switch'mechanism while said switching element is locked against furthersliding movement by said locking portion.

5 A push-button'device as set forth 'in'claim '4 wherein :said lockingportion has a shape such that at least one edge thereof remains inengagement with "said frame member during the tilting of the switchingelement.

References Cited in the file of this patent UNITED STATES PATENTS1,158,355 Willis Oct. 26, 1915 1,316,372 Liebreich Sept. 16, 19191,559,427 Hemphill Oct. 27, 1925 2,156,946 Closson et al. May 2, 19392,445,635 Poliakoff July 20, 1948 2,453,035 Ponsy Nov. 2, 1948

